Ignition-plug for internal-combustion engines



L. LAVOISIER. IGNITION PLUG FOR INTERNAL COMBUSTION ENGINES.

APPLIc'ATIoN FILED IAN. 2;. I918.

Patented J an. 6, 1920.

kw a m N m R w n m Wm N LUCIEN LAVOISIER, OF PARIS, FRANCE.

IGNITION -PLU'G FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented Jan. 6, 1920.

Application filed January 21, 1918. Serial No. 213,015.

To all whom it may concern:

H Be it known that I, LUoIEN LAvoismR, a citizen of the Republic of France, residing at Paris, 14 ter Rue du Colonel Oudot,

5 Seine Department, in the Republic of France, engineer, have invented certain new and useful Improvements in Ignition-Plugs for Internal combustion Engines, of which the following is a specification.

My inventlon has for its object an ignition plug for internal combustion motors which differs essentially from ordinary ignition plugs by its central rod or electrode being bored and provided "with apertures in such a way asto allow the surrounding air entering it up to its inner end. This arrangement has for effect to provide for effective cooling of the central electrode and of the whole center part of the body of the plug, thus resulting in extending the duration of its use and in increasing thesecurity of working.

One way of carrying out my improved ignition plug is shown in'the accompanying drawing by way. of example, in a sectional view.

1 designates a threaded bush adapted to be screwed into the wall of the cylinder of the engine and made with a flared seat 2. The insulatingqmember 3 which surrounds the central electrode is made with a double cone shaped strengthened portion and is clamped between said seat 2 and an externally threaded clamping ring 4 adapted to be screwed into the aperture of the bush 1, itsinner conical surface bearing upon, the exterior coneshaped portion of the strengthened part of the insulator, 3. This arrangement-will secure perfect tightness of thedevice. I

The central electrode consistsof a bored rod 5 closed at its inner end, said inner end being formed with an inverted dished portion or flange 6.extending up to a short distance from the inside of the inner end 0 the bush 1.

The insulated part 3 is secured on the rod 5 between a shoulder 7 formed by said dished portion of the rod and a nut 8 with a washer interposed between the parts to prevent unscrewing, ortwithout any washer.

The portion of the electrode situate above I the nut 8 has a number of holes 9 drilled through it so as to reduce its weight and to permit the surrounding air of circulating freely through said electrode.

The different parts of the ignition plug are sized and shaped so as to reduce as much as possible the masses of the metal parts.

The outer diameter of the dished portion 6 is slightly smaller than the smallest inner diameter of the bush 1 so as to allow the electrode'of being removed and of being replaced without unscrewing the bush 1 from the engine.

The aforesaid arrangements make the construction of the ignition plug simple, strong and easy to take to pieces; the center portion of the i ition plug is cooled to a perfectly reliab e extent, and the fixedness of the insulating member and its perfect tlghtness are in the same time secured in a most reliable and lasting manner.

In the example described and shown in the drawing, the upper portion of the ign tion plug is left uncovered, but if desired, 1t

may be capped by means'of any appropriate mounting, such as a lid, a cup or the like, which ought to be pierced w th appropriate apertures to permit of cooling the center part of the ignition plu It is to be understood that t e insulating member may be formed of any appropriate material such as 'molded mlca, mlca disks or the like.

Having now particularly described and i ascertained the nature of my said invention,

and in what manner the same is be erformed, I declare that what I cla1m 1s:

1. An ignition plug comprismg a seat or bottom, an insulating member fixed on said seat, a bored center rod fixed in the insulating member, said bored rod being open above," closed below by a thn1 bottom, having lateral apertures relatively large exclusively placed above the insulating member, the interior space-of said bored rod being completely free. 2. A11 ignition plug, comprlsmg a seat or bottom, an insulating member fixed on said seat, a bored center rod fixed in the v insulating member, said bored rod being as my invention I have signed my name in open above, having lateral apertures relapresence of tWo subscriblng Witnesses.

tively large exclusively placed above the inv sulat-ing member and closed belowby this LAVOISIER LUCIEN' 5 bottom provided with a raised edge which Witnesses:

is directed toward the exterior of the plug. CHARLES BAUDRY,

In testimony that I claim the foregoing CHAS. P. Pmassmzv 

